Instrument and method for implanting an interbody fusion device

ABSTRACT

A holder is provided which couples to the spine. In an embodiment, the holder has two conduits into which sleeves may be inserted during a spinal fusion procedure. The holder may have a distractor extending from the bottom of the holder. The distractor secures the holder to the spine and maintains a proper separation distance between adjacent vertebrae. The sides of the distractor may be serrated to better secure the holder to the spine. The sleeves and conduits serve as alignment guides for instruments and implants used during the procedure. In an embodiment, the holder may include holes for fasteners that fixably secure the holder to vertebrae adjacent to a disk space. A flange may be placed around the holder to shield surrounding tissue and to provide a placement location for adjacent blood vessels during the spinal fusion procedure.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention generally relates to spinal fixation andfusion systems. The invention also generally relates to an insertionguide used during the insertion of a spinal implant system, wherein theimplant system is used for correction, fixation, and/or stabilization ofthe spine.

[0003] 2. Description of the Related Art

[0004] Intervertebral disks that become degenerated due to variousfactors such as trauma or aging typically have to be partially or fullyremoved. Removal of an intervertebral disk can destabilize the spine,making it necessary to replace the vertebral disk to maintain the heightof the spine and to fuse the spine. Spinal implants are often used toprevent collapse of the spine. In a typical spinal fusion procedure, anintervertebral disk is removed and implants are inserted in the diskspace between neighboring vertebrae. The implants maintain normal diskspacing and help restore spinal stability.

[0005] The implants may be constructed of any biocompatible materialssufficiently strong to maintain spinal distraction including, but notlimited to, bone, stainless steel, or inert metals. Implants aretypically packed with bone graft or a synthetic bone graft substitute tofacilitate spinal fusion. Implants may have a variety of shapes, whichinclude, but are not limited to, threaded cylinders, unthreadedcylinders, and parallelepipeds.

[0006] An anterior spinal fusion procedure is often preferred to aposterior spinal fusion procedure. An anterior spinal fusion proceduremay require less bone removal and muscle distraction than a posteriorspinal fusion procedure. Also, an anterior spinal fusion procedure mayinvolve less risk of nerve damage than a posterior spinal fusionprocedure. In an anterior spinal fusion procedure, a surgical opening inthe abdomen may be up to ten inches deep. A protective sleeve may beused during preparation and insertion of a spinal implant. Theprotective sleeve may serve to protect abdominal organs, blood vesselsand other tissue during the spinal implant procedure. The sleevetypically extends above the surgical opening during use. The sleeve maymaintain distraction of the vertebrae. Also, the sleeve may serve as analignment guide for tool and implant insertion during the surgicalprocedure.

[0007] Protective sleeves typically have distractors on a distal end.Distractors are projections that may be inserted into a disk spaceduring a spinal fusion procedure. The distractors may serve to achieveand maintain distraction of adjacent vertebrae. Distractors may alsohelp to secure the protective sleeve to the spinal column during theprocedure. Protective sleeves may have one tube or two parallel tubes.FIG. 1 shows a single-tube protective sleeve, and FIG. 2 shows adual-tube protective sleeve.

[0008]FIG. 1 illustrates a single-tube protective sleeve 30 used in aspinal fusion procedure. A spinal fusion procedure involves theinsertion of one or more implants in a disk space between two vertebrae.Protective sleeve 30 includes a substantially long, hollow tube 32, twodistractors 34 on opposite sides of an end of the tube, and two spikes36 (only one shown) on opposite sides of the end of the tube. Protectivesleeve 30 is typically sufficiently long to allow access to a spinalcolumn of a large patient during an anterior procedure. Protectivesleeve 30 may also be used in a posterior spinal fusion procedure.

[0009] A spinal fusion procedure using implants typically involves theinsertion of two implants that are bilaterally positioned in anintervertebral disk space. During an anterior procedure, the disk spaceis prepared by performing a discectomy and by distracting the vertebraeadjacent the disk space. A cap (not shown) is placed on end 38 of theprotective sleeve 30 opposite distractors 34 to protect the end of thesleeve during insertion. Distractors 34 may then be hammered into thedisk space by striking the cap with a mallet (not shown). Spikes 36 arehammered into disk bone on the vertebrae and help to stabilizeprotective sleeve 30 during the procedure. Distractors 34 serve toseparate the adjoining vertebrae to approximately normal spacing.

[0010] After insertion, a hole is drilled in the disk space by insertinga tool with a reaming head attachment through tube 32 and rotating thetool until a predetermined depth is reached. In some procedures, thehole is then tapped by inserting a tool with tap head attachment throughtube 32 and rotating the tool until a predetermined depth is reached.The top and bottom of the reamed and tapped hole may extend into the endplates of the adjacent vertebrae. After the hole is prepared, an implantmay be inserted in the hole by attaching the implant to an implantinsertion tool and inserting the implant through tube 32. For untappedholes, the implant may be hammered into the hole by striking the implantinsertion tool with a mallet. For tapped holes, the implant may bethreaded into the hole by turning the implant insertion tool. Then, theprotective sleeve 30 may be removed.

[0011] If a second implant is to be inserted, the protective sleeve 30is hammered in the disk space opposite the first implant and theprocedure is repeated. Alternatively, the protective sleeve 30 mayremain inserted in the disk space, and a second single-tube protectivesleeve 30 may be inserted adjacent to the protective sleeve.

[0012] The optimal alignment and spacing of implants in a spinal fusionprocedure may be determined before surgery. Achieving the predeterminedalignment and spacing during surgery is often important for optimalfusing of the adjacent vertebrae. Protective sleeve 30 hascharacteristics that may make achieving alignment difficult. First, eachof the two holes is aligned, reamed, and tapped in a separate procedure.It is often difficult to align and space the holes correctly. Second,the alignment of protective sleeve 30 must be maintained afterinsertion. Any slight movement of protective sleeve 30, which may actlike a lever arm, may result in misalignment of the hole.

[0013]FIG. 2 illustrates a dual-tube protective sleeve 40 used in aspinal fusion procedure involving the insertion of two implants into adisk space. Protective sleeve 40 includes substantially long, hollowtubes 32, one or more distractors 34 and one or more spikes 36.Protective sleeve 40 is typically long enough to allow access during ananterior procedure to an intervertebral disk in a large patient. Spinalfusion using implants with protective sleeve 40 involves the insertionof two implants, bilaterally positioned in parallel in an intervertebraldisk space. During an anterior procedure, the disk space is prepared byperforming a discectomy and by distracting the vertebrae adjacent thedisk space. A cap (not shown) is placed on the end 42 of protectivesleeve 40 opposite distractor 34 to protect the sleeve during insertion.Distractor 34 is then hammered into the disk space by striking the capwith a mallet (not shown). Spikes 36 are hammered into disk bone on theadjacent vertebrae to help stabilize protective sleeve 40 during theprocedure. Distractor 34 serves to separate the adjoining vertebrae toapproximately normal spacing. After insertion, holes are reamed in thedisk space by inserting a tool with a reaming head attachment throughtubes 32 and rotating the tool until a predetermined depth is reached.In some procedures, the holes are tapped by inserting a tool with a taphead attachment through tubes 32 and rotating the tool until apredetermined depth is reached. The top and bottom of the reamed andtapped holes may extend into the end caps of the adjacent vertebrae.After the holes are prepared, implants are inserted in the holes byattaching the implants to an implant insertion tool and inserting theimplants through tubes 32. For untapped holes, the implants are hammeredinto the hole by striking the implant insertion tool with a mallet. Fortapped holes, the implants are threaded into the holes by turning theimplant insertion tool. After both implants are inserted, protectivesleeve 40 is removed.

[0014]FIG. 3 shows a representation of implants inserted into disk space44 using a dual-tube protective sleeve 40. Spinal nerves in the spinalcanal 46 are protected by dura 48. Nerves 50 extend from the spinalcanal 46. Implants 52 are inserted between two vertebrae 54 (one shown).Care must be taken during insertion of the implants 52 to make sure thatthe implants do not impinge on the nerves 50.

[0015] Like single-tube protective sleeve 30, dual-tube protectivesleeve 40 has characteristics that make it difficult to align theimplants correctly. First, the alignment of protective sleeve 40 must bemaintained after insertion. Any slight movement of sleeve 40, which mayact like a lever arm, may result in misalignment of the hole. Second,the long parallel tubes make it difficult to angulate the two implants52 relative to each other. Angulated implants may be the desiredalignment in some spinal fusion procedures. Using a dual-tube protectivesleeve 40 has the advantage that the surgical procedure is simplifiedbecause there is only one insertion procedure, as opposed to twoinsertion procedures for a single-tube protective sleeve 30.

[0016] Single- and dual-tube protective sleeves share somedisadvantages. First, the sleeves are typically unitary members that arelong enough to extend out of a ten-inch deep surgical opening afterbeing hammered into place. To maintain alignment after insertion, thesleeve must be kept as motionless as possible. The sleeve tends to actlike a lever arm, and any slight motion of the sleeve during theprocedure may result in misalignment of the implants. The sleeve actingas a lever arm is particularly problematic when the sleeve is handed offduring the surgical procedure from one member of the surgical team toanother member of the surgical team.

[0017] A second disadvantage of protective sleeves is related to thefirst disadvantage. The sleeve is held in place only by the distractorsand the spikes inserted in the disk space. This connection may not bevery secure. Because the connection is not secure, the sleeve may haveto be held by the members of the surgical team throughout the entireprocedure to maintain proper alignment. As noted above, any slightmovement can result in the misalignment of the implants.

[0018] A third disadvantage of protective sleeves is that they mayafford minimal protection to surrounding tissues during a spinal fusionprocedure. Major blood vessels, parallel the anterior surface of thespine for much of the spine's lower length. These vessels may beretracted during the procedure. The interface between the distal end ofthe sleeve and the spinal column is typically not a perfect fit. Gapsmay exist between the sleeve and the vertebrae. The presence of gapscreates the risk of drill bits, taps, and implants coming into contactwith the blood vessels or other surrounding tissues during theprocedure. Also, the blood vessels may be pinched between the sleeve andthe vertebrae. A nick or cut to either the aorta or the blood vesselscan be life threatening.

[0019] The above-mentioned methods and systems inadequately address theneed to angulate implants in some spinal fusion procedures, the need tomaintain precise alignment throughout the procedure, and the need toprotect surrounding tissues during the procedure. It is thereforedesirable that an improved method and system be derived for insertingspinal implants during a spinal fusion procedure.

SUMMARY OF THE INVENTION

[0020] The problems outlined above may in large part be solved by aholder or base that allows for the insertion of instruments and spinalimplants into a disk space during a spinal fusion procedure. In anembodiment, distractors and tangs of a holder may be driven into anintervertebral disc space. The distractors and tangs may secure theholder to the spine during. In an embodiment, fasteners extendingthrough a holder into the adjacent vertebrae may be used fix the holderto the spine. In another embodiment, distractors, tangs, and fastenerssecure a holder to the spine. A flange may be placed around the holderto protect the surrounding tissue and blood vessels. Protective sleevesmay be inserted into and may be removed from conduits in the holder. Aportion of the sleeve may have a slot or a window, located adjacent tothe top of the holder. The slot or window may serve as a view-port toprovide increased visibility near the procedure site. Surgicalinstruments may be inserted through the protective sleeves and throughthe holder conduits to prepare the intervertebral space for an implant.

[0021] An embodiment of a holder includes a body, one or more conduitspassing through the body from the top to the bottom, one or moredistractors on the bottom of the body, and one or more tangs on thebottom of the body. The body may have a smooth outer surface with nosharp corners. In some embodiments, the body may be flared near thebottom to provide shielding for surrounding tissue. The flared bottommay provide room for optional fasteners to extend at oblique angles fromthe body of the holder. The flared body may also provide the holder witha stable base against the spinal column.

[0022] An optional flange may be provided that fits around the outersurface of the holder. The flange may provide shielding of soft tissue,such as blood vessels and organs, from cutting tools at the junction ofthe holder and the vertebral bodies. The flange may also prevent damageto soft tissues due to pinching of the soft tissue between the holderand the vertebral bodies. The flange may be made of a rigid orsemi-rigid material. A portion of the flange may be made of an elasticmaterial so that the flange may stretch over and slide down the holder.In one embodiment, the holder may include a rim for holding the flangein place after installation. In another embodiment, the holder mayinclude a groove for holding the flange in place. In another embodiment,the flange has an elastic collar, which holds the flange in placeagainst the holder.

[0023] In some embodiments, the inner surfaces of the conduits maycontain shoulders to limit the insertion distance of protective sleevesin the conduits. Above a shoulder, a conduit may be sized to match theouter diameter of a protective sleeve. Below the shoulder, the conduitmay be sized to match the outer diameter of instrument heads andimplants to be used in the procedure. In some embodiments, the shouldermay include slots configured to engage distractors on protectivesleeves; thus allowing the holder to be used with single-tube protectivesleeves having distractors.

[0024] Embodiments of the holder may have non-circular conduits. Thecross sectional shape of the holder conduits and the protective sleevesinserted into the holder may be any desired shape that allows for theinsertion of spinal implants into a disk space. For example, the crosssectional shape of the conduits may be rectangular if the crosssectional shape of the spinal implants are generally rectangular. Otherembodiments of the holder may have circular conduits or conduits whichdo not have a regular geometric shape. Embodiments of holders that havecircular conduits may be constructed with conduits of differentdiameters to accommodate protective sleeves and implants of differentdiameters.

[0025] Embodiments of holders may be provided with non-parallel angledconduits. Non parallel conduits allow the insertion of implants atoblique angles to improve spinal fusion and to protect nerves posteriorto the disk space. Other holder embodiments may have parallel conduits.

[0026] The distractors on the bottom of the holder body are projectionsthat insert into a disk space during a spinal fusion procedure. Thedistractors may serve to achieve and/or maintain distraction of theadjacent vertebrae. The distractors may also secure the holder to thespinal column during the procedure. The distractors may be substantiallywedge-shaped, and may include curved surfaces. The tangs on the bottomof the holder body may serve to maintain distraction, and may alsomaintain a parallel orientation of the vertebrae during the procedure.The tangs may also be substantially wedge-shaped, and may also includecurved surfaces. Outer surfaces of the distractors and tangs may beserrated to secure the holder to adjacent vertebrae during a spinalfusion procedure.

[0027] In one embodiment, there is one distractor centrally locatedbetween two conduits; and two tangs, with one next to each conduitopposite the distractor. Curved inner surfaces on the tangs and curvedsurfaces on the distractor may serve as partially enclosed extensions ofthe conduits, and may help maintain alignment of the implant during aspinal fusion procedure.

[0028] In some embodiments, the body includes one or more fastener holesfor the insertion of fasteners into vertebrae. The fastener holes may beangled so that fasteners inserted through the holes extend obliquelyinto adjacent vertebrae without damaging the vertebral endplates. Thefasteners may pass through the end caps of the vertebrae into cancellousbone in the interior of the vertebrae. The fasteners may serve tosubstantially anchor the holder to the spine during the spinal fusionprocedure.

[0029] The height of the holder, when inserted in a spine, may besubstantially less than the length of a protective sleeve. During thespinal fusion procedure, a protective sleeve may be inserted into aholder conduit when needed and removed when not needed without affectingalignment. Removal of a protective sleeve from the holder decreases thelikelihood of a protective sleeve being inadvertently used as a leverarm during the procedure. Removing a protective sleeve from the holdermay increase visibility at the procedure site. Removing a protectivesleeve may also allow for easy irrigation of the entire surgical site,including the holes being prepared for the implants.

[0030] The ability to remove the protective sleeves when not in use, theshort profile of the holder, and the fastener anchoring system all helpto maintain proper alignment during the insertion of implants in aspinal fusion procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further advantages of the present invention will become apparentto those skilled in the art with the benefit of the following detaileddescription of embodiments and upon reference to the accompanyingdrawings in which:

[0032]FIG. 1 illustrates a single-tube protective sleeve;

[0033]FIG. 2 illustrates a dual-tube protective sleeve;

[0034]FIG. 3 is a representation of implants inserted into a disk spacewith a dual-tube protective sleeve, or with an embodiment of a holder ofthe present invention that has parallel conduits;

[0035]FIG. 4 is a perspective view of a first embodiment of a holder;

[0036]FIG. 5 is a front view the first embodiment holder;

[0037]FIG. 6 is a side view the first embodiment holder;

[0038]FIG. 7 is a cross-sectional view of the first embodiment holdertaken substantially along line 7-7 of FIG. 6;

[0039]FIG. 8 is a cross-sectional view of the first embodiment holdertaken substantially along line 8-8 of FIG. 5;

[0040]FIG. 9 is a top view of the first embodiment holder;

[0041]FIG. 10 is a bottom view of the first embodiment holder;

[0042]FIG. 11 is a top view of an embodiment of a holder flange;

[0043]FIG. 12 is a top view of another embodiment of a holder flange;

[0044]FIG. 13 is a perspective view of an embodiment of a holder flangewith a collar;

[0045]FIG. 14 is a perspective view of an embodiment of a holder flange;

[0046]FIG. 15 is a perspective view of an embodiment of a holder withoutconduit extenders;

[0047]FIG. 16 is a cross sectional view of an embodiment of a holderhaving a flange groove;

[0048]FIG. 17 is a cross sectional view of an embodiment of a holderwithout body flare;

[0049]FIG. 18 is a cross sectional view of an embodiment of a holderwith an alternative fastener hole arrangement;

[0050]FIG. 19 is a perspective view of an embodiment of a holder havingserrated distractors and tangs;

[0051]FIG. 20 is a perspective view of an embodiment of a holder havingan extended upper opening and an insertion tool slot.

[0052]FIG. 21 is a perspective view of the embodiment shown in FIG. 20;

[0053]FIG. 22 is a perspective view of an insertion tool for anembodiment of a holder;

[0054]FIG. 23 is a perspective view of an alternate embodiment holderhaving overlapping conduits;

[0055]FIG. 24 is a top view of a possible arrangement of implantsinserted into a disk space using the holder of FIG. 23;

[0056]FIG. 25 is a perspective view of a holder having one conduit;

[0057]FIG. 26 is a perspective view of a holder with an insertedprotective sleeve and tool;

[0058]FIG. 27 is a front view of a holder with an alternate protectivesleeve;

[0059]FIGS. 28a-28 e illustrate steps included in a spinal fusionprocedure using an embodiment of a holder;

[0060]FIG. 29 illustrates the positioning of major blood vessels aroundone embodiment of a holder during a typical L5/S1 fusion procedure,

[0061]FIG. 30 illustrates the positioning of major blood vessels aroundone embodiment of a holder during a typical L4/L5 fusion procedure; and

[0062]FIG. 31 illustrates the angulation of implants inserted using oneembodiment of a holder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] Referring to the drawings, a holder or base for use as aninsertion guide during a spinal implantation procedure is designatedgenerally as 100. A holder may be used to support a sleeve during aspinal fusion procedure, and a base may be used with or without a sleeveduring a spinal fusion procedure. For illustrative purposes only, thefollowing description will describe a holder. A person having ordinaryskill in the art will understand that a holder may be used as a base,and a base may be used as a holder.

[0064] FIGS. 4-10 show views of a first embodiment of the holder 100.The holder 100 may include unitary body 102, conduits 104 through thebody, conduit extenders 106, flared portion 108, flange rim 110, holes112, distractor 114, and tangs 116. The height of the holder body may beless than about six inches. Preferably, the holder height is less thanfour inches, and more preferably, less than 2 inches.

[0065] The conduits 104 may have circular cross sections. Alternatively,the conduits 104 may have any desired cross sectional shape, such asrectangular or ellipsoid, to correspond to instruments and implants usedduring a spinal fusion procedure.

[0066] As shown in FIG. 6, the body 102 may have flared portion 108. Theflared portion 108 may allow for angulation of fastener holes 112, asshown in FIG. 8. Fastener holes 112 may be located in slot 118.Angulated fastener holes 112 allow fasteners 120 inserted through thefastener holes to penetrate adjacent vertebrae 54 through end caps 122of the vertebrae and into cancellous bone 124, as shown in FIG. 28c.Attaching the holder 100 to the vertebrae 54 with fasteners 120 placedthrough end caps 122 may minimize weakening of the end plates 126 of thevertebrae. Shoulders 128 limit the insertion depth of the fasteners 120into the holder 100. Fasteners 120 may be any type of fastening deviceincluding, but not limited to, screws, nails, rivets, trocars, pins, andbarbs.

[0067] The flared portion 108 of the body 102 may shield blood vessels,nerves, and other soft tissue from damage by the body and tools usedduring the spinal fusion procedure. In addition, the flared portion 108increases the circumference of holder 100 to a maximum near flange rim110. Optional flange 130 may slip over the top of holder 100 and resideagainst the rim 110. The flared portion 108 may also provide a stablebase on the end caps 122 of the vertebrae 54 for holder 100.

[0068] The perimeter of the conduit 104 at a top end of the holder 100may match the outer perimeter of protective sleeve 132 inserted into theconduit. The conduits 104 may include shoulders 134. A shoulder 134prevents insertion of a protective sleeve 132 into a conduit 104 beyonda certain depth. As shown in FIG. 9 and in cross section in FIG. 7, aconduit 104 may include slots 136. The slots 136 correspond to the shapeof the distractors 34 on the ends of single-tube protective sleeves 30.Slots 136 allow a holder 100 to be used with a single-tube protectivesleeve 30 having distractors 34, such as the sleeve shown in FIG. 1. Inother embodiments, conduits 104 may be configured to receive protectivesleeves 132 without distractors 34 by having shoulders 128 which extendfully around the diameter of the conduits 104. A protective sleeve 132may be slid into a conduit 104 without the use of an insertion tool.

[0069]FIG. 7 shows a cross sectional view of the first embodiment holder100 with the conduits 104 angulated toward one another. Having theconduits angled relative to one another allows for the angulation ofimplants 52. Angulated implants 52 may provide a more stable fusion ofvertebrae 54. In addition, angulated implants 52 may be less likely toprotrude from posterior side 138 of the disk space to press on nerves 50exiting the spinal canal 46. The angle A, located between a center lineof a first conduit 104 and a centerline of an adjacent conduit, may varyfrom 0 to about 30 degrees, preferably the angle A is less than about 20degrees, and more preferably, the angle A is less than about 10 degrees.If the angle A is 0 degrees, then the adjacent conduits 104 areparallel.

[0070] Flange rim 110 may support flange 130. The flange 130 may serveto protect blood vessels and other tissue placed upon the flange 130 andnear the body 102 of the holder 100. FIGS. 11-14 show some flangeembodiments. In one embodiment, ends 140 of the flange 130 arerelatively wide to provide extra protection and a support area on thesides of the holder 100 where the blood vessels are most likely to beplaced. As shown in FIG. 14, the flange 130 may have flexible collar 142to more securely attach the flange to the body 102 of a holder 100. Theshape of the flange 130 during use may correspond to the anteriorsurface of the spine so that a snug fit against the spine is establishedduring a spinal fusion procedure. The snug fit may help prevent toolsused during the procedure from contacting and potentially damagingadjacent tissue. The flange 130 may be made of a semi-rigid elastic orplastic material so that an inner edge of the flange conforms to theshape of the holder body 102 after the flange has been stretched overand slid down the body. As shown in FIG. 14, the flange may have narrowbrims 144, and relatively short ends 140. The ends 140 of the flange 130are long enough to be easily positionable under adjacent vessels andtissue.

[0071] The distractors 114 and tangs 116 are protrusions, which mayextend from the bottom of the holder body 102. Distractor 114 may serveto maintain distraction of adjacent vertebrae 54 during a spinal fusionprocedure. The distractor 114 may establish a separation distancebetween the vertebrae during the procedure. Tangs 116 may also serve tomaintain distraction. The tangs may maintain a parallel orientation ofthe vertebrae 54 during the procedure. Distractor 114 and tangs 116 maybe substantially wedge-shaped to facilitate insertion into the diskspace 44. Surfaces of distractor 114 and tangs 116 may be curved tomatch the curvature of the conduits 104, so that the distractor andtangs serve as partially enclosed extensions of conduits.

[0072] Bottom 146 of the holder 100, as seen in FIG. 5, may conform tothe general shape of a vertebra 54. When the holder is inserted into adisk space 44, portions of the bottom 146 of the holder 100 may resideon end caps 122 of adjacent vertebrae 54. Having the bottom 146 of theholder 100 shaped to conform to the shape of the vertebrae 54 may helpto protect adjacent soft tissue and vessels from being pinched betweenthe holder and the vertebrae during the spinal fusion procedure.

[0073] FIGS. 15-21 show some alternate embodiments of a holder 100. FIG.15 shows a holder without conduit extenders on the body 102. FIG. 16shows a cross sectional view of a holder 100 with flange groove 148. Theflange groove 148 may support an inner edge of a flange 130 to hold theflange at a desired position on the body 102. FIGS. 16 and 17 show crosssectional views of holders 100 without fastener holes. FIG. 17 alsoshows the holder without a flared portion and without a flange rim or aflange groove.

[0074]FIG. 18 shows a cross sectional view of another embodiment holderwith an alternate fastener hole 112 arrangement. In this embodiment,fastener holes 112 extend between conduits 104 from the top of body 102downwards at an oblique angle relative to a vertical axis of holder 100.The fastener holes 112 cross at point 150 and then exit near an outeredge of the lower portion of body 102. The fastener holes 112 includeshoulders 128 to limit the insertion depth of fasteners 120 intofastener holes 112. To use this embodiment, one fastener 120 is insertedinto a fastener hole 112 and into a vertebra 54 until the head of thefastener is past the cross point 150. Then, another fastener 120 isinserted into the remaining fastener hole 112 and the fastener isinserted into the adjacent vertebra 54. Both fasteners 120 may befurther inserted into the vertebrae 54 until the fastener heads contactthe shoulders 128.

[0075]FIG. 19 shows an embodiment of a holder 100, which has serrations154 on outer edges of the distractor 114 and on the outer edges of thetangs 116. Serrations 154 may maintain proper alignment and theserrations may inhibit the distractor 114 and tangs 116 from backing outof the vertebrae 54 after the holder 100 is inserted during a spinalfusion procedure.

[0076]FIG. 20 and FIG. 21 show perspective views of an alternateembodiment of a holder 100. The body 102 may include flat sections 156,large top opening 158, undercut tool slots 160, spring stop 162, andball 164. The flat sections 156 may help to make the holder 100 easierto machine during the manufacturing. The holder may have large topopening 158 with conduits 104 located in a lower section of the body.The body 102 may have undercut tool slots 160 (only one shown). Coilsprings (not shown) are placed in the body 102 between the spring stops162 and the balls 164 (only one shown). The spring stops 162, coilsprings and balls 164 form an assembly that removably connects aninsertion tool 166 to the holder 100.

[0077]FIG. 22 shows a perspective view of the insertion tool 166 usedwith the holder shown in FIG. 20 and FIG. 21. The insertion tool 166includes attachment head 168, dimples 170, shaft 172, and top member174. The attachment head 168 of the insertion tool 166 is inserted intothe top opening 158 of the body 102. The insertion tool 166 is rotatedapproximately 90 degrees. Rotating the insertion tool 166 forces theballs 164 in the holder body 102 against the coil springs, andcompresses the springs. When the dimples 170 align with balls 164, thesprings force the balls into the dimples and attach the insertion tool166 to the holder 100. When the holder 100 is attached to the insertiontool 166, the insertion tool functions as a handle and allows the holderto be positioned at a desired location. A mallet (not shown) may be usedto strike upper surface 176 of the top member 174 to insert the holderinto a disk space 44 after the holder is positioned at a desiredlocation. To remove the insertion tool 166 from the holder 100, theinsertion tool is rotated approximately 90 degrees, and the attachmenthead 168 is removed from the opening 158.

[0078]FIG. 23 shows a perspective view of an embodiment of a holder 100wherein the conduits 104 of the holder overlap. The holder has a pair ofdistractors 114 located at opposite sides of the body 102. FIG. 24 showsa schematic representation of one possible arrangement of implants 52,53 inserted in a disk space 44 with the, embodiment of a holder 100shown in FIG. 23.

[0079]FIG. 25 shows an embodiment of the holder 100 having one conduit104 extending through the body 102. The holder 100 may have a pair ofdistractors 114 located at opposite sides of the conduit 104. The holdermay have fastener holes (not shown) that allow fasteners to attach theholder to vertebrae 54 during a spinal fusion procedure.

[0080]FIG. 26 illustrates an embodiment of a holder 100 with protectivesleeve 132, driver 180, and attachment 182. Tube 32 of protective sleeve132 may be inserted in one of the conduits 104 of holder 100. Shaft 184of driver 180 may be inserted in tube 32. At least a portion of shaft184 may have a diameter substantially equal to the inside diameter oftube 32 to maintain alignment of the driver 180 during use. Stop 186 mayserve to limit the distance shaft 184 may be inserted into tube 32. Insome embodiments, stop 186 may be adjustable to allow differentinsertion depths. The driver 180 may have handle 188 for turning shaft184 located on an end of the shaft. Attachment 182 may be located on anend of the shaft opposite to the handle 188. Attachments may include,but are not limited to, drilling heads and tapping heads. An implant 52may also be coupled to the distal end of a driver for insertion into adisc space 44.

[0081]FIG. 27 illustrates an embodiment of a protective sleeve 132 priorto insertion into an embodiment of a holder 100. The protective sleeve132 includes widened portion 190 at an end of the sleeve. The widenedportion 190 receives a tool (not shown) having a complementary wideportion at an end of the tool. The sleeve 132 may include view-port 192to provide improved visibility of the surgical site during theprocedure. The view-port may be a window, a slot, or other structurethat allows increased allows increased visibility of the surgical siteduring the procedure.

[0082]FIGS. 28a-28 e illustrate steps included in a spinal fusionprocedure using an embodiment of a holder 100. In FIG. 28a, holder 100is shown being inserted into disk space 44 between adjacent vertebrae54. Distractor 114 may be driven into the disk space 44 by strikinginsertion device 194 with mallet 196. Insertion device 194 may fit inthe conduits 104. Alternately, insertion device 194 may fit betweenconduits 104 in slot 118 to provide a contact surface with the holder100 for hammering. In the embodiments of the holder 100 shown in FIGS.20, 21, and 23, the insertion device may be an insertion tool 166 asshown in FIG. 22. The insertion device 194 may be coupled with holder100 prior to insertion into the surgical cavity, and may be used as ahandle for inserting and positioning holder 100 by the surgeon prior toand during hammering. Distractor 114 separates vertebrae 54 as thedistractor is hammered in. The distractor widens the disk space 44 tothe desired width for the procedure. Holder 100 may be hammered with themallet 196 until the bottom 146 of body 102 makes substantial contactwith the adjacent vertebra 54.

[0083] In FIG. 28b, holder 100 has been hammered into the disk space 44to an optimal depth. Optional flange 130 may then be slipped over thetop of holder 100 to fit snugly against flange rim 110. After flange 130is installed, blood vessels 198, such as the aorta and vena cava, whichare retracted to one side during the installation of the holder 100, maybe placed over flange 130 next to body 102, as shown in FIG. 29 and FIG.30. The shape of flange 130 serves to protect the blood vessels 198 frombeing pinched, nicked or cut during the remainder of the spinal fusionprocedure. Body 102 may be formed with smooth, arcuate outer surfaceswith no sharp comers to further protect blood vessels 198 and tissue.

[0084]FIG. 28c shows the insertion of optional fasteners 120 in fastenerholes 112, through end caps 122 and into cancellous bone 124 ofvertebrae 54. Angling of fasteners 120 into cancellous bone 124 avoidsvertical penetration deep into the end plates 126; thus helping toprevent weakening of the endplates near the implants 52. The head ofdriver 200 may fit into slot 118 to contact a fastener 120. The slot 118may protect surrounding soft tissues should the head of the driver 200slip off the fastener 120. Slot 118 may also help contain a fastener 120should the fastener be dropped during the insertion process. In someembodiments, the heads of fasteners 120 may include hex or star shapedslots for receiving a corresponding driver 200. In some embodiments,driver 200 may include a bent or bendable shaft to facilitate the angledinsertion of the fasteners 120 in the fastener holes 112. In someembodiments, the shaft of driver 200 may be long enough to allow thesurgeon to turn the driver above the surgical cavity while the head ofthe driver is coupled to the head of a fastener 120. In someembodiments, a fastener 120 may be coupled to the driving head of driver200 to help prevent dropping the fastener into the surgical cavityduring insertion.

[0085] In FIG. 28d, protective sleeve 132 is inserted in one of theconduits 104 of the holder 100. Shaft 184 of driver 180 is inserted intothe protective sleeve 132. Stop 186 serves to limit the distance shaft184 may be inserted into sleeve 132. Drilling head 182 may be coupled tothe distal end of driver 180. A handle (not shown) coupled to theproximal end of driving shaft 184 may be turned while applying downwardpressure on driver 180 to drill out a hole in disk space 44. Drillingthe hole may also remove bone from the end plates 126 of adjacentvertebrae 54. Flange 130 may protect adjacent blood vessels 198 andother soft tissues during the drilling process.

[0086] In spinal fusion procedures using threaded implants, after thehole is drilled, driver 180 is retracted and a tap (not shown) isattached to the driver. The tap and the driver 180 are inserted into thesleeve 132. A handle (not shown) coupled to an end of the driving shaft184 is turned while applying downward pressure on driver 180 to tap aflight of threads in the vertebrae 54. After a flight of threads isformed in the hole, the driver is removed from the protective sleeve132.

[0087] Referring to FIG. 28e, a threaded implant 52 is coupled to thedistal end of an implant insertion tool 202. The implant insertion tool202 is inserted into the sleeve 132. A handle (not shown) coupled to theproximal end of implant insertion tool 132 is turned while applyingdownward pressure to screw implant 52 into the threaded hole in diskspace 44.

[0088] In spinal fusion procedures using unthreaded implants, after thehole is drilled, an unthreaded implant 52 is coupled to an end of animplant insertion tool 202. The implant insertion tool 202 is insertedinto the protective sleeve 132. A mallet (not shown) is used to strikethe proximal end of implant insertion tool 202 to drive implant 52 intothe disk space 44.

[0089] In all embodiments, inserted implant 52 is then detached frominsertion tool 202. Protective sleeve 132 may then be removed from theconduit 104 of holder 100 and inserted into the adjacent holder conduit104. Optionally, a second protective sleeve 132 may be inserted in theadjacent conduit 104. The steps described for FIGS. 28d-28 e may then berepeated for the installation of the second implant. After the secondimplant 52 is installed, fasteners 120 may be backed out of vertebrae 54and holder 100 may be removed from the disk space 44.

[0090] An advantage of holder 100 illustrated in FIGS. 28a-28 e is thatthe tools and protective sleeve 132 may be removed at any time duringthe procedure without affecting the alignment or spacing of the holder100. Fixing the holder 100 to the vertebrae with fasteners 120, andinserting the protective sleeve 132 into the holder 100 only whennecessary may minimize the risk of misalignment of implants 52 during aspinal fusion procedure.

[0091]FIG. 29 illustrates the positioning of major blood vessels 198around a dual-conduit holder 100 during an L5/S1 fusion procedure.Holder 100 is shown inserted in disk space 44 (L5/S1) between vertebra54 (L5) and sacrum 204 (S1). The bifurcation of major blood vessels 198(the aorta and vena cava) typically is proximate vertebra L5. The rightbranch and left branch of major blood vessels 198 are shown separatedand placed over holder flange 130. In some patients, the bifurcationpoint of the major blood vessels 198 may be located higher or lower thanproximate the L5 vertebra. An irregularly located bifurcation point ofthe major blood vessels 198 may require the branches of the major bloodvessels to be routed around one side of holder 100.

[0092]FIG. 30 illustrates the positioning of major blood vessels 198around a holder 100 during an L4/L5 fusion process. Holder 100 is showninserted in disk space 44 (L4/L5) between adjacent vertebrae 54 (L4 andL5). The bifurcation of major blood vessels 198 typically is proximatevertebra L5. The major blood vessels 198 are shown placed over holder100 upon flange 130. The blood vessels may be placed on either side ofholder 100.

[0093] The configuration of holder 100 and the added protection offlexible flange 130 may serve to protect the blood vessels 198 frombeing nicked during the spinal fusion procedure. In addition, the body102 of holder 100 may be curved and may lack sharp comers or edges tofurther protect the blood vessels 198 and other tissue from abrasion.Protecting the blood vessels 198 is critical in a spinal fusionprocedure, as the aorta is a major artery and the vena cava is a majorvein. Even a tiny nick in either blood vessel 198 is potentiallycatastrophic, and must be repaired quickly. A nick in the vena cava isparticularly problematic because the vena cava has thinner walls thanthe aorta, making the vena cava easier to nick and harder to repair thanthe aorta.

[0094]FIG. 3 illustrates the orientation of implants 52 inserted usingdual-tube protective sleeves 40 or an embodiment of holder 100 that hasan angle A value of 0 degrees. Implants 52 are shown inserted inparallel in disk space 44. Spinal nerves within the spinal canal 46 andprotective sheath 48 (also called the dura) are shown posterior to diskspace 44. Nerves 50 exit the sides of spinal canal 46. An end 206 of animplant 52 may put pressure on nerves 50 if the implant is inserted farenough to allow ends to protrude out the posterior side 138 of diskspace 44. Pressure on the nerves may lead to severe post-operative painor nerve damage for the patient.

[0095]FIG. 31 illustrates the angulation of implants inserted using oneembodiment of a holder 100. Implants 52 are shown inserted angledinwards in disk space 44. Nerves 50 are shown exiting from the sides ofspinal canal 46. If implants 52 are inserted far enough that ends 206protrude out the posterior side 138 of the disk space 44, ends 206 maybe more likely to put pressure on dura 48 than on nerves 50. Dura 48 maybe less likely to be negatively affected by the pressure than nerves 50.

[0096] Also shown in FIG. 31 is an embodiment of a holder 100 insertedin disk space 44. The curvature of bottom 146 of holder 100 maysubstantially match the curvature of the anterior surface of theadjacent vertebrae 54. The close fit between the vertebrae 54 and theholder 100 may help protect blood vessels 198 and other soft tissuesfrom being pinched between the vertebrae and the holder during thespinal fusion procedure. The angulation of conduits 104 is shown asangle A. Different embodiments of holder 100 may be made with a widerange of angles A to be used in spinal fusion procedures requiringdifferent optimal angulations of implants 52. Most procedures may fallbetween 0 degrees and 30 degrees. Approximately 8 degrees may be theoptimal angulation for implants 52 in many procedures.

[0097] Further modifications and alternative embodiments of variousaspects of the invention will be apparent to those skilled in the art inview of this description. Accordingly, this description is to beconstrued as illustrative only and is for the purpose of teaching thoseskilled in the art the general manner of carrying out the invention. Itis to be understood that the forms of the invention shown and describedherein are to be taken as examples of embodiments. Elements andmaterials may be substituted for those illustrated and described herein,parts and processes may be reversed, and certain features of theinvention may be utilized independently, all as would be apparent to oneskilled in the art after having the benefit of this description of theinvention. Changes may be made in the elements described herein withoutdeparting from the spirit and scope of the invention as described in thefollowing claims.

What is claimed is:
 1. A holder for use with a sleeve during a spinalfusion procedure, comprising: a body; at least one protrusion extendingfrom the body, the at least one protrusion configured to couple the bodyto a disk space between a first vertebra and a second vertebra; and aconduit through the body; wherein an end of the sleeve is removablypositionable in the conduit during use, and wherein the sleeve isconfigured to allow tools or devices for implanting a spinal fusiondevice, or for preparing a patient to receive a spinal fusion device, tobe inserted in the disk space through the sleeve and through theconduit.
 2. The holder as defined in claim 1, further comprising ashoulder in the conduit, the shoulder configured to limit insertiondepth of the sleeve into the conduit.
 3. The holder as defined in claim1, wherein the at least one protrusion establishes a separation distancebetween the first vertebra and the second vertebra during use.
 4. Theholder as defined in claim 1, wherein the at least one protrusioncomprises sides and further comprising serrations on at least one sideof the at least one protrusion.
 5. The holder as defined in claim 1,further comprising a flange, the flange having an inner edge, an outeredge, a lower surface and an upper surface, wherein the flange ispositionable around the body, and wherein the flange is configured toprotect tissue and vessels adjacent to the disk space during use.
 6. Theholder as defined in claim 5, wherein the flange is made of a semi-rigidmaterial.
 7. The holder as defined in claim 5, wherein the lower surfaceof the flange curves during use to substantially match curvatures ofsurfaces of vertebrae adjacent to the holder.
 8. The holder as definedin claim 5, further comprising a rim on a portion of an outer surface ofthe body, wherein the rim is configured to engage the lower surface ofthe flange to support the flange during use.
 9. The holder as defined inclaim 5, further comprising a groove on a portion of an outer surface ofthe body, wherein the groove is configured to engage the inner edge ofthe flange to support the flange during use.
 10. The holder as definedin claim 5, wherein the flange further comprises an elastic collarconfigured to conform to the shape of the body during use to support theflange during use.
 11. The holder as defined in claim 1, wherein aheight of the body is less than about six inches.
 12. The holder asdefined in claim 1, wherein a height of the body is less than about fourinches.
 13. The holder as defined in claim 1, wherein a height of thebody is less than about two inches.
 14. The holder as defined in claim1, further comprising a hole in the body, the hole configured to receivea fastener that couples the body to the first vertebra.
 15. The holderas defined in claim 14, wherein the hole passes through the body at anoblique angle relative to a vertical axis of the body.
 16. The holder asdefined in claim 1, further comprising a slot in a conduit wall, theslot configured to engage a distractor on an end of the sleeve duringuse.
 17. The holder as defined in claim 1, wherein the sleeve furthercomprises a view-port to provide increased visibility of a surgical siteduring use.
 18. The holder as defined in claim 1, wherein the bottom ofthe body is curved to substantially conform to curvatures of vertebraeadjacent to the holder during use.
 19. A base for use during a spinalfusion procedure, comprising: a body having a height of less than about6 inches, said body comprising a conduit through the body; and at leastone protrusion extending from the body, the at least one protrusionconfigured to couple the body to a disk space between a first vertebraand a second vertebra; wherein the conduit is configured to allow toolsor devices for implanting a spinal fusion device, or for preparing apatient to receive a spinal fusion device, to be inserted in the diskspace through the conduit.
 20. The base as defined in claim 19, furthercomprising a sleeve, and wherein an end of the sleeve is removablypositionable in the conduit.
 21. The base as defined in claim 20,further comprising a slot in a conduit wall, the slot configured toengage a distractor on an end of the sleeve during use.
 22. The base asdefined in claim 20, further comprising a shoulder in the conduit, theshoulder configured to limit insertion depth of the sleeve into theconduit.
 23. The base as defined in claim 20, wherein the sleeve furthercomprises a view-port to provide increased visibility of a surgical siteduring use.
 24. The base as defined in claim 19, wherein the at leastone protrusion establishes a separation distance between the firstvertebra and the second vertebra during use.
 25. The base as defined inclaim 19, wherein the at least one protrusion comprises sides andfurther comprising serrations on at least one side of the at least oneprotrusion.
 26. The base as defined in claim 19, further comprising aflange, the flange having an inner edge, an outer edge, a lower surfaceand an upper surface, wherein the flange is positionable around thebody, and wherein the flange is configured to protect tissue and vesselsadjacent to the disk space during use.
 27. The base as defined in claim26, wherein the flange is made of a semi-rigid material.
 28. The base asdefined in claim 26, wherein the lower surface of the flange curvesduring use to substantially match curvatures of surfaces of vertebraeadjacent to the holder.
 29. The base as defined in claim 26, furthercomprising a rim on a portion of an outer surface of the body, whereinthe rim is configured to engage the lower surface of the flange tosupport the flange during use.
 30. The base as defined in claim 26,further comprising a groove on a portion of an outer surface of thebody, wherein the groove is configured to engage the inner edge of theflange to support the flange during use.
 31. The base as defined inclaim 26, wherein the flange further comprises an elastic collarconfigured to conform to the shape of the body during use to support theflange during use.
 32. The base as defined in claim 19, wherein a heightof the body is less than about four inches.
 33. The base as defined inclaim 19, wherein a height of the body is less than about two inches.34. The base as defined in claim 19, further comprising a hole in thebody, the hole configured to receive a fastener that couples the body tothe first vertebra.
 35. The base as defined in claim 34, wherein thehole passes through the body at an oblique angle relative to a verticalaxis of the body.
 36. The base as defined in claim 19, wherein thebottom of the body is curved to substantially conform to curvatures ofvertebrae adjacent to the holder during use.
 37. A base for use during aspinal fusion procedure, comprising: a body; a first hole in the body,the hole configured to receive a fastener that couples the body to afirst vertebra during use; and a conduit through the body; wherein theconduit is configured to allow tools or devices for implanting a spinalfusion device, or for preparing a patient to receive a spinal fusiondevice, to be inserted in a disk space adjacent to the first vertebra.38. The base as defined in claim 37, further comprising a second hole inthe body, the second hole configured to receive a fastener that couplesthe body to a second vertebra during use.
 39. The base as defined inclaim 37, further comprising a sleeve, and wherein an end of the sleeveis removably positionable in the conduit.
 40. The base as defined inclaim 39, further comprising a shoulder in the conduit, the shoulderconfigured to limit insertion depth of the sleeve into the conduit. 41.The base as defined in claim 39, further comprising a slot in a conduitwall, the slot configured to engage a distractor on an end of the sleeveduring use.
 42. The base as defined in claim 39, wherein the sleevefurther comprises a view-port to provide increased visibility of asurgical site during use.
 43. The base as defined in claim 37, furthercomprising a protrusion extending from the body, the protrusionconfigured to be positionable within the disk space during use.
 44. Thebase as defined in claim 43, wherein the protrusion establishes aseparation distance between the first vertebra and the second vertebraduring use.
 45. The base as defined in claim 43, wherein the protrusioncomprises sides and further comprising serrations on at least one sideof the protrusion.
 46. The base as defined in claim 37, furthercomprising a flange, the flange having an inner edge, an outer edge, alower surface and an upper surface, wherein the flange is positionablearound the body, and wherein the flange is configured to protect tissueand vessels adjacent to the disk space during use.
 47. The base asdefined in claim 46, wherein the flange is made of a semi-rigidmaterial.
 48. The base as defined in claim 46, wherein the lower surfaceof the flange curves during use to substantially match curvatures ofvertebrae adjacent to the holder.
 49. The base as defined in claim 46,further comprising a rim on a portion of an outer surface of the body,wherein the rim engages the lower surface of the flange to support theflange during use.
 50. The base as defined in claim 46, furthercomprising a groove on a portion of an outer surface of the body,wherein the groove engages the inner edge of the flange to support theflange during use.
 51. The base as defined in claim 46, wherein theflange further comprises an elastic collar which conforms to the shapeof the body during use to support and secure the flange against thebody.
 52. The base as defined in claim 37, wherein a height of the bodyis less than about six inches.
 53. The base as defined in claim 37,wherein a height of the body is less than about four inches.
 54. Thebase as defined in claim 37, wherein a height of the body is less thanabout two inches.
 55. The base as defined in claim 37, wherein the firsthole passes through the body at an oblique angle relative to a verticalaxis of the body.
 56. The base as defined in claim 37, wherein thebottom of the body is curved to substantially conform to curvatures ofvertebrae adjacent to the holder during use.
 57. A holder for use with asleeve during a spinal fusion procedure comprising: a body; a firstconduit through the body; a second conduit through the body; and aprotrusion from a bottom of the body, the protrusion configured tocouple the body within a disk space between a first vertebra and asecond vertebra; wherein the sleeve is removably positionable within thefirst conduit or the second conduit, and wherein the sleeve isconfigured to allow tools or devices for implanting a spinal fusiondevice, or for preparing a patient to receive a spinal fusion device, tobe inserted in the disk space through the sleeve and through theconduit.
 58. The holder as defined in claim 57, further comprising ashoulder in the first conduit, wherein the shoulder limits insertiondepth of the sleeve into the first conduit.
 59. The holder as defined inclaim 57, wherein the protrusion establishes a separation distancebetween the vertebrae during use.
 60. The holder as defined in claim 57,wherein the protrusion has sides and further comprising serrations on atleast one side of the protrusion.
 61. The holder as defined in claim 57,wherein the protrusion is located between exit holes of the first andsecond conduits in the bottom of the body.
 62. The holder as defined inclaim 61, further comprising a second protrusion extending from thebottom of the body adjacent to a side of the exit hole of the firstconduit opposite the first protrusion, the second protrusionpositionable between adjacent vertebrae during use.
 63. The holder asdefined in claim 62, wherein the second protrusion further comprisesserrations on a side of the second protrusion.
 64. The holder as definedin claim 57, further comprising a second protrusion extending from thebottom of the body adjacent to a side of the first conduit, and a thirdprotrusion extending from the bottom of the body adjacent to a side ofthe exit hole of the second conduit, wherein the first protrusion ispositioned between the second protrusion and the third protrusion. 65.The holder as defined in claim 64, wherein the second protrusion furthercomprises serrations on a side of the second protrusion.
 66. The holderas defined in claim 57, further comprising a hole passing through thebody, the hole configured to receive a fastener that couples the holderto a vertebra during use.
 67. The holder as defined in claim 66, whereinthe hole passes through the body at an oblique angle relative to avertical axis of the body.
 68. The holder as defined in claim 57,wherein the bottom of the body is curved to substantially conform tocurvatures of vertebrae adjacent to the holder during use.
 69. Theholder as defined in claim 57, further comprising a flange, the flangehaving an inner edge, an outer edge, a lower surface, and an uppersurface, wherein the flange is positionable around the body, and whereinthe flange is configured to protect tissue and vessels adjacent to thedisk space during use.
 70. The holder as defined in claim 69, whereinthe flange is made of a semi-rigid material.
 71. The holder as definedin claim 69, wherein a lower surface of the flange curves during use tosubstantially match curvatures of surfaces of vertebrae adjacent to theholder.
 72. The holder as defined in claim 69, wherein the flangefurther comprises an elastic collar configured to conform to the shapeof the body during use to support the flange.
 73. The holder as definedin claim 69, further comprising a rim on a portion of an outer surfaceof the body, wherein the rim is configured to engage the lower surfacethe flange during use.
 74. The holder as defined in claim 69, furthercomprising a groove on a portion of an outer surface of the body,wherein the groove is configured to engage the inner edge of the flangeduring use.
 75. The holder as defined in claim 57, wherein the firstconduit further comprises a slot on an inner surface, the slotconfigured to engage a distractor on an end of the sleeve during use.76. The holder as defined in claim 57, wherein the first and secondconduits are substantially parallel.
 77. The holder as defined in claim57, wherein the conduits are angled relative to each other.
 78. Theholder as defined in claim 77, wherein a distance between a centerlineof the first conduit and a centerline of the second conduit at a top ofthe body is greater than a distance between centerlines of the conduitsat the bottom of the body.
 79. The holder as defined in claim 78,wherein an angle between the centerlines of the conduits is less thanabout 30 degrees.
 80. The holder as defined in claim 78, wherein anangle between the centerlines of the conduits is less than about 20degrees.
 81. The holder as defined in claim 78, wherein an angle betweenthe centerlines of the conduits is between about 2 degrees and about 10degrees.
 82. The holder as defined in claim 57, wherein the body furthercomprises two sides, and wherein the sides flare such that a largestwidth of the body measured from side to side is proximate the bottom ofthe body.
 83. The holder as defined in claim 57, further comprising afirst hole and a second hole passing through the body and wherein thefirst hole and the second hole are configured to receive fasteners forcoupling the holder to vertebrae during use.
 84. The holder as definedin claim 83, wherein the first hole and the second hole are obliquelyangled through the body relative to a vertical axis of the body.
 85. Theholder as defined in claim 83, wherein the body further comprises: afirst side and a second side; and wherein the holes are located betweenthe first and second conduits; wherein an entry of the first hole islocated on a top of the body proximate the first side, and an exit ofthe first hole is located on the bottom of the body proximate the secondside; and wherein an entry of the second hole is located on the top ofthe body proximate the second side, and an exit for the second hole islocated on the bottom of the body proximate the first side.
 86. Theholder as defined in claim 83, wherein the body further comprises: afirst side and a second side; and an opening in a top of the body, theopening having a bottom; wherein an entry of the first hole is locatedsubstantially at the bottom of the opening near the first side, and anexit of the first hole is located on the bottom of the body proximatethe first side; and wherein an entry for the second hole is locatedsubstantially at the bottom of the opening near the second side, and anexit for the second hole is located on the bottom of the body proximatethe second side.
 87. The holder as defined in claim 86, wherein theopening is located between the first conduit and the second conduit. 88.The holder as defined in claim 57, wherein a height of the body is lessthan about six inches.
 89. The holder as defined in claim 57, wherein aheight of the body is less than about four inches.
 90. The holder asdefined in claim 57, wherein a height of the body is less than about twoinches.
 91. The holder as defined in claim 57, wherein a portion of thefirst conduit overlaps a portion of the second conduit.
 92. The holderas defined in claim 57, wherein the sleeve further comprises a view-portto provide increased visibility of a surgical site during use.
 93. Abase for use during a spinal fusion procedure, comprising: a body; afirst conduit through the body; a second conduit through the body; and ahole in the body, the hole configured to receive a fastener that couplesthe body to a first vertebra during use; wherein tools or devicesinserted into the first conduit or the second conduit during use arepositionable in a disk space adjacent to the first vertebra.
 94. Thebase as defined in claim 93, further comprising a second hole in thebody, the second hole configured to receive a fastener that couples thebody to a second vertebra during use.
 95. The base as defined in claim93, further comprising a sleeve, and wherein an end of the sleeve isremovably positionable in the first conduit or the second conduit duringuse.
 96. The base as defined in claim 95, wherein the sleeve furthercomprises a view-port to provide increased visibility of a surgical siteduring use.
 97. The base as defined in claim 95, further comprising ashoulder in the first conduit, wherein the shoulder limits insertiondepth of the sleeve into the first conduit.
 98. The base as defined inclaim 95, wherein the first conduit further comprises a slot on an innersurface, the slot configured to engage a distractor on an end of thesleeve during use.
 99. The base as defined in claim 93, wherein thebottom of the body is curved to substantially conform to curvatures ofvertebrae adjacent to the holder during use.
 100. The base as defined inclaim 93, further comprising a flange, the flange having an inner edge,an outer edge, a lower surface, and an upper surface, wherein the flangeis positionable around the body, and wherein the flange is configured toprotect tissue and vessels adjacent to the disk space during use. 101.The base as defined in claim 100, wherein the flange is made of asemi-rigid material.
 102. The base as defined in claim 100, wherein alower surface of the flange curves during use to substantially matchcurvatures of surfaces of vertebrae adjacent to the holder.
 103. Thebase as defined in claim 100, wherein the flange further comprises anelastic collar configured to conform to the shape of the body during useto support the flange.
 104. The base as defined in claim 100, furthercomprising a rim on a portion of an outer surface of the body, whereinthe rim is configured to engage the lower surface the flange during use.105. The base as defined in claim 100, further comprising a groove on aportion of an outer surface of the body, wherein the groove isconfigured to engage the inner edge of the flange during use.
 106. Thebase as defined in claim 93, wherein the first and second conduits aresubstantially parallel.
 107. The base as defined in claim 93, whereinthe conduits are angled relative to each other.
 108. The base as definedin claim 107, wherein a distance between a centerline of the firstconduit and a centerline of the second conduit at a top of the body isgreater than a distance between centerlines of the conduits at thebottom of the body.
 109. The base as defined in claim 108, wherein anangle between the centerlines of the conduits is less than about 30degrees.
 110. The base as defined in claim 108, wherein an angle betweenthe centerlines of the conduits is less than about 20 degrees.
 111. Thebase as defined in claim 108, wherein an angle between the centerlinesof the conduits is between about 2 degrees and about 10 degrees. 112.The base as defined in claim 108, wherein t he body further comprisestwo sides, and wherein the sides flare such that a largest width of thebody measured from side to side is proximate the bottom of the body.113. The base as defined in claim 93, wherein the first hole and thesecond hole are obliquely angled through the body relative to a verticalaxis of the body.
 114. The base as defined in claim 93, wherein the bodyfurther comprises: a first side and a second side; and wherein the holesare located between the first and second conduits; wherein an entry ofthe first hole is located on a top of the body proximate the first side,and an exit of the first hole is located on a bottom of the bodyproximate the second side; and wherein an entry of the second hole islocated on the top of the body proximate the second side, and an exitfor the second hole is located on the bottom of the body proximate thefirst side.
 115. The base as defined in claim 93, wherein the bodyfurther comprises: a first side and a second side; and an opening in atop of the body, the opening having a bottom; wherein an entry of thefirst hole is located substantially at the bottom of the opening nearthe first side, and an exit of the first hole is located on a bottom ofthe body proximate the first side; and wherein an entry for the secondhole is located substantially at the bottom of the opening near thesecond side, and an exit for the second hole is located on the bottom ofthe body proximate the second side.
 116. The base as defined in claim93, wherein the opening is located between the first conduit and thesecond conduit.
 117. The base as defined in claim 93, wherein a heightof the body is less than about six inches.
 118. The base as defined inclaim 93, wherein a height of the body is less than about four inches.119. The base as defined in claim 93, wherein a height of the body isless than about two inches.
 120. The base as defined in claim 93,wherein a portion of the first conduit overlaps a portion of the secondconduit.
 121. A method of inserting an implant during a spinal fusionprocedure, comprising: inserting a holder in a disk space between afirst vertebra and a second vertebra, wherein a portion of the diskspace is beneath a first conduit, wherein the first conduit extendsthrough the holder from a top to a bottom of the holder; securing theholder to the first vertebra and the second vertebra; placing a sleeveinto the first conduit of the holder; preparing the disk space beneaththe first conduit to receive a first implant with instruments insertedthrough the sleeve and through the first conduit; and inserting animplant into the disk space through the first conduit.
 122. The methodas defined in claim 99, further comprising: removing the sleeve from thefirst conduit of the holder; placing a sleeve in a second conduit of theholder, the second conduit extending through the holder from the top tothe bottom; preparing the disk space beneath the second conduit toreceive an implant with instruments inserted into the disk space throughthe sleeve and holder; and inserting a second implant into the diskspace through second conduit.
 123. The method as defined in claim 121,further comprising placing a flange about an outer surface of the holderafter the holder is inserted into the disk space to shield surroundingtissue and vessels during use.
 124. The method as defined in claim 121,wherein the holder comprises at least one distractor, and whereininserting the holder in a disk space comprises coupling a first end of aholder insertion device to the holder and hammering on a second end ofthe holder insertion device to drive the distractor into the disk spacebetween the second vertebra and the first vertebra.
 125. The method asdefined in claim 121, wherein the holder comprises a first hole and asecond hole through the body, and wherein securing the holder to thefirst vertebra and the second vertebra comprises placing a fastener inthe first hole and inserting the fastener into the first vertebra,placing a second fastener in the second hole and inserting the secondfastener into the second vertebra.
 126. The method as defined in claim125, wherein the holder comprises a distractor extending from the bottomand positionable between the vertebrae to maintain a separation distancebetween the vertebrae.